Refrigerated multiple shelf display case



March 10, 1953 M. H. s'rRANG REFIGERATED MuLTlPLE SHELF DISPLAY CASE 4 Sheets-Sheet 2 Filed Feb. 11, 1950 OCOOOOOOCOOOOOOOOOO OODOODDOOOOODOOOOOO 00000000000000000000 OOOQOOOOOOOOOOOOOOO OCODOODOOOOODOOOODO QOODCOOOOOOOOOOOOO ODOOOJDOCOOO 000 ooooo 00000 ooooO OgOOOUO Patented Mar. 10, 1953 REFRIGERATED MULTIPLE SHELF DISPLAY CAS Minor H. Strang, Marshall, Mich., assignor to Sherer-Gillett Company, Marshall, Mich., a corporation of Illinois Application February 11, 1950, Serial No. 143,738

8 Claims. l`

My invention relates to improvements in multiple shelf refrigerated display case or counter and has for one object to provide a display case of the open, self-service type wherein food may be stored, displayed in a refrigerated atmosphere while still available for withdrawal by the customer without the necessity of opening doors, shutters or the like.

I propose to maintain the refrigerated atmosphere in the counter by the use of a forced draft blower system, utilizing a cooling coil or member beneath the display door of the lower secf tion. Air will be forced by fan or other suitable means over or through the coil or cooler and pass across a plurality of display shelves above the floor. shelf through return ducts at the rear of the case. The air will be returned from the lower shelf through return openings near the front of the case but a single cooling element will be used to provide the cooled air for both of the i display shelves or floors in the counter.

One important factor is that in an open type self-service case, the velocity of air discharged over the shelf or shelves must be kept low to avoid loss of air over the front glass or wall of the shelf. On the other hand, a substantial volume of air must be circulated through the cooling unit in order that the unit may operate at a sufficiently high suctiontemperature to give economical operation. `This is accomplished in my invention by circulating a portion of the air through the cooling element or coil, discharging it upwardly through the duct system so that it passes over and about the food on display and another portion of the air is recirculated from the fan through the cooling coil back to the low pressure side of the fan and again through the cooling coil. Thus the fan accomplishes the purpose of recirculating air through the cooling coil and also recirculating air through and around the food on display and offered for sale.

Other objects will'appear from time to time throughout the specification and claims.

My invention is illustrated more or less diagrammatically in the accompanying drawings,

whereini Figure 1 is a vertical section through the counter embodying my invention; i

Figure 2 is a section along the line 2--2 of Figure 1;

FigureS Figure 1;

Figure 4 is is a` section along the line 3 3 of a section along the line 4`4 `of The air will` be returned from the topv Figure 5 is a section along the line 5--5 of Figure 1.

Like parts are indicated by like characters throughout the specification and drawings.

The body of 4my counter comprises an outer shell I and an inner shell 2, forming bottom, back, front and ends of the counter, the space between these shells being filled with a suitable insulator 3. The counter stands on legs 4. The insulated back 5 of the counter is higher than the insulated front 8 of the counter. Projecting upwardly from the counter front 6 is a glass panel l, preferably of double glass for insulation without interfering with visibility. Extending upwardly from the back 5 of the counter is a housing 8 which carries a mirror 9, light I0, light shield II and shelf I2. This housing is insulated only along its lower surface as at I3. A

I4 is a shelf or floor within the housing. It has a front wall I5 spaced inwardly from the front of the counter to define an air passage I6. It has a back wall I1 extending upwardly from the shelf or floor I4 to a point substantially in line with the top of the glass wall 'I. Partitions I8 assist in positioning the wall I'I and this licor or shelf is supported at each end on the end walls of the housing. The wall I'I is spaced inwardly from the back of the counter body to define an air passage 48. Below the floor I4 is a fan I9 driven by a motor 20, drawing air from a low pressure chamber 2l,` discharging it through a passage 22, through the cooling coils or cooling element 23 and thence into` the space 48 behind the wall Il. Suspended above the door I4 on the wall I'I is a housing 24 defining an air passage 25, communicating with the passage 48 so that air from the passage 48 passes through the housing and is discharged through the opening 26 above the floor` I4. This cold air passes forwardly and downwardly through the passage I6 back to the chamber 2| so that the fan circulates air through the cooling coil and across the floor I4.

Above the housing or air box 24 is the upper shelf 2'I supported on apertured top flanges 28 on the wall I'I and on the counter body. This shelf has a forward wall 29 spaced at about the same horizontal level as the top of the glass panel I with a further glass partition SIJeXtending upwardly therefrom. y N

Beneath the shelf 2l, between it and the housing 24 is an air passage or chamber 3i, communicating through a port Sla, with the space above the shelf 2l. At the back of the shelf 2'I communicating with the passage4 48v'and supported Vreturned through the passage or port on the underside of the housing 8 is an air duct 32 having perforate diffuser walls which receive air from the chamber 48 and discharge it into the space between the mirror 9, the shelf 2l, and the partition 30, this cold air being drawn back through the chamber 3| and returned, as will hereinafter appear, to the chamber 2|.

33 is a baiiie in the passage 48 to divide the cold air, part of it going into the air passage and part going into the passage 32 so that the air drawn by the fan feeds both the `area immediately above the main shelf and the area immediately above the auxiliary shelf.

Referring now to Figure 2, 34 indicates two air chambers or passages, one on either side of the chamber 3|. The spent air from chamber 3| moves laterally to right and yleft into chainbers 34 downwardly through the passages 35 into the horizontal passages 36 and thence backv to the chamber 2|, thus permitting separate circulation of -cold air discharged from the cooler across both the storage and display shelves and the separate return of the spent air to the low pressure side of the fan.

3l indicates a chamber below the chamber 22, communicating with passages 33 on either side thereof, which passages in turn communicate with the chamber 2| thus providing a by-pass duct through which part of the air circulated by the fan through the cooling coil leaves the passage 48, enters the chamber 31, the cham- ;bers '38, to return to the chamber 2|.

It will be noted that while the cold air enters the space immediately above the lower shelf I4 in van extended zone, that air passes out to be I6 throughout substantially the whole length of the shelf, thus insuring circulation of refrigerated air throughout this entire area. With respect to the upper shelf, the air is admitted to the shelf through the chamber or duct 32 throughout substantially the entire length of the shelf and returns through the passage Sla to insure proper circulation throughout the -entire shelf area. It is not necessary that both intake and exhaust for each shelf extend the enoth'er extend throughout the entire length because under these circumstances the air is adequately circulated.

VThe by-pass duct arrangement is of the ut- `most importance because in the use of counters shopper, too rapidly desiccate the food and cause the wasteful spillage of cold air out of the display Ycounter into the sales room and thereby unpleasantly cooling the customers near ythe counter and also wasting the power required for refrigeration.

I claim: Y Y

1. A multiple shelf, open top, self-service Adisplay Vcase for foods Yand the like including a plurality of display shelves,lone'above the other, adapted to receive food for display and sale, a refrigerating element, a fan adapted to force air through such element, supply and Areturn ducts associated with theA fan and the refrigeryating element leading separately to and from each shelf vand means for controlling the Vvelocity of the air discharged over the shelves com- `prisi-ng V-a -by-'pass ductadapted to receive part tire Vshelf length. It is sufficient that one or the of the cooled air from the refrigerating element and return it directly to the low pressure side of the fan.

2. A multiple shelf, open top, self-service display case for foods and the like including a plurality of display shelves, one above the other, adapted to receive food for display and sale, a refrigerating element, a fan adapted to force air through such element, supply and return ducts associated with the fan and the refrigerating element leading separately to and from each shelf, and means for controlling the velocity of the air over the shelves comprising a by-pass duct adapted to receive part of the cooled air from the refrigerating element and return it directly to the low pressure side of the fan, the supply ducts foreach shelf discharging thereabove adjacent the back of the display case, the return ducts receiving air from the shelf adjacent the front of the display case.

3. A multiple shelf, open top, self-service display case for foods and the like including a plurality of display shelves, one above the other, adapted to receive food for display and sale, a refrigerating element, a fan adapted to force air through such element, supply and return ducts associated with the fan and the refrigerating element leading separately to and from each shelf, and means for controlling the velocity of the air over `the shelves comprising a by-pass duct adapted to receive part of the cooled air from the refrigerating element and return it directly to the low pressure .side of the fan, there being supply and return ports, one along the front, the other along the rear edge of the display case, one of the ports extending along the entire counter edge of the display case, the other extending a shorter distance adjacent the center of the opposite edge of the display case.

4. A multiple shelf, open top, self-service `display case for foods and the like including a housing open at the top, having front and back walls, the back wall being higher than the front wall, a lower shelf in the case below the top of the front wall, ran upper shelf above 4the lower shelf extending forwardly from the back wall but terminating short of the front wall, each shelf having a'back wall, transparent air-tight partitions vextending upwardly fromV Ythe front of 'both shelves, air ports located adjacent the front partition and back wall of each shelf, a fan, a cooling coil, a passage joining them, this passage and vcooling coil being on the high pressure side of conduits leading from the cooling coil to the one Vset 'of ports associated with each shelf, return passages extending between the other set of ports associated with veach shelf and the low pressure chamber, and means for controlling the velocity of the air through the conduits andover the shelves comprising a by-pass `conduit leading from the coil directly to the low pressure chamber and by-passing al1 the shelves.

5. In an open top, self-service display case having a shelf, means for cooling air, a fan adapted to force air through the cooling means, a cold air supply conduit leading from the cooling means to the shelf, a spent air return conduit leading from theY shelf to the fan, and means `for controlling the velocity of the air over the shelf comprising .a .by-pass and conduitadapted to receive a part of the cold air discharge by the fan through the cooling element and return such cold air to the fan for further circulation.

6. In an open top, self -service display case having a shelf, means for cooling air, a fan adapted to force air through the cooling means, a cold air supply conduit leading from the cooling means to the shelf, a spent air return conduit leading from the shelf to the fan, and means for controlling the Velocity of the air over the shelf comprising a by-pass and conduit adapted to receive a part of the cold air discharged by the fan through the cooling element and return such cold air to the fan for further circulation, the conduits being so disposed that the recirculated cold air is mixed with the air from the spent air return conduit before it is recirculated through the fan.

7. The method of displaying and storing foodstuffs which consists in maintaining a cold air food storage zone open only from above, supplying cold air under pressure from a refrigerating zone thereto, withdrawing spent air therefrom, and returning it for circulation through the refrigerating zone and regulating the velocity of the ycool air in the food storage zone by recirculating some of the cold air through the refrigerating zone while preventing the entrance of such recirculated cold air into the food storage space.

8. The method of displaying and storing foodstuffs which consists in maintaining a cold air food storage zone open only from above, supplying cold air under pressure from a refrigerating zone thereto, withdrawing spent air therefrom and returning it for circulation through the refrigerating zone, regulating the velocity of the cool air in the food storage zone by recirculating some of the cold air` through the refrigerating zone while preventing the entrance of such recirculated cold air into the food storage space, and mixing the spent air from the food storage zone before it is recirculated through the refrigerating zone.

MINOR H. STRANG.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,198,449 Atkins Apr. 23, 1940 2,236,190 Wolfert Mar. 25, 1941 2,428,717 Moores Oct. 7, 1947 2,447,760 MacMaster Aug. 24, 1948 2,511,375 Raskn June 13, 1950 2,528,916 Shreve Nov. 7, 1950 

